It is known that heteropolysaccharides can be produced by certain microorganisms. Some of such heteropolysaccharides function as hydrophilic colloids and because of their viscosity properties and rheology have been used as thickening agents for aqueous systems.
Organisms classified as Agrobacterium radiobacter IFO (Institute of Fermentation, Osaka) 12607, IFO 12664, IFO 12665, IFO 13127, IFO 13256, IFO 13532 and IFO 13533 have been used to produce exocellular polysaccharides (Hisamatsu, et al., "Acidic Polysaccharides Containing Succinic Acid in Various Strains of Agrobacterium", Carbohydrate Research, 61 (1978) 89-96). These organisms were grown in a synthetic medium described in Amemura, et al., Hakko Kogaku Zasshi; 49 (1971) 559-564, Chem. Abst. 75, 1971, 74882j.
An exopolysaccharide containing D-glucose, D-galactose, pyruvic acid, and O-acetyl groups in the approximate proportions 6:1:1:1.5 is described by L. P. T. M. Zevenhuizen, "Methylation Analysis of Acidic Exopolysaccharides of Rhizobium and Agrobacterium", Carbohydrate Research, 26 (1973) 409-419. The organisms used by Zevenhuizen are described as A. tumefaciens A-8 and A-10.